Loadcenter



Filed June 30, 1967 2 Sheets-Sheet 1 1969 J. T. ATTRIDGE 3,462,648

LOADCENTER FIG.2.

III/11111 11 I WITNESSES z? ATTORNEY Aug. 19, 1969 J- T. ATTRIDGE LOADCENTER 2 Sheets-Sheet 2 Filed June 30, 1967 FIG.9.

FIG.8.

3,462,648 LOADCENTER John T. Attridge, Trumbull, Conu., assignor to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed June 30, 1967, Ser. No. 650,482

, Int. Cl. H02b 1/04 US. Cl. 31799 10 Claims ABSTRACT OF THE DISCLOSURE An improved loadcenter comprises an insulating support block and a bus assembl captured in place on the support block when the support block is mounted on a base plate.

Brief summary of the invention An improved loadcenter comprises relatively few parts that are relatively inexpensive to manufacture and assemble. Two bus assemblies are moved into cavity means in an insulating block through a bottom opening of the insulatin block and captured in place when the insulating block is secured to the base of the receptacle. Each of the bus assemblies comprises a stab part and a screwtype terminal part. The bus assemblies are moved into cavity means in an insulating block through a bottom opening of the insulating block and captured in place when the insulating block is secured to the base of the receptacle. The bus assemblies engage a flat insulating plate that is positioned between the insulating block and the base plate to limit downward movement of the assemblies, and the stab parts are provided with notch means that receive projectingvparts of the insulating block to limit movement of the bus assemblies in the cavities whereby the bus assemblies are adequately supported in the cavities against the forces that may be applied thereto when circuit breakers are connected to the stabs or when the screws of the terminal parts are worked to connect or disconnect conductors to the terminal parts.

-Objects of the invention An object of this invention is to provide an improved loadcenter comprising an insulating support black, a bus assembly and a base plate with securing means securing the insulating support block to the base plate and capturing thebus assembly'in a mounted position.

' Another object of this invention is to provide an improved loadcenter comprising a base plate and an insulating support block having cavity means therein with an improved bus assembly positioned in the cavity means and with securing means securing the support block to a base plate and capturing the bus assembly in position.

Another object of this invention is to provide an improved loadcenter comprising an improved bus assembly, comprising no more than three separate pieces, and means mounting the bus assembly in a loadcenter receptacle.

A more general object'of this invention is to provide an improved loadcenter having a reduced number of parts, which loadcenter is relatively inexpensive to'manufacture and easy to assemble.

These and other objects of the invention will be apparent from the following description when taken in conjunction with the accompanying drawings.

In said drawings:

FIGURE 1 is a plan view, with parts broken away, of a loadcenter constructed-in accordance with the principles of this invention;

FIG. 2 is a sectional view taken generally along the line II)-II of FIG. 1;

" United States Patent ice FIG. 3 is a sectional view taken generally along the line III-III of FIG. 1;

FIG. 4 is a sectional view taken generally along the line IVIV of FIG. 1;

FIG. 5 is a bottom view of the insulating support block of FIG. 1 with one of the bus assemblies of FIG. 1 being positioned in the associated cavity;

FIG. 6 is an exploded view, partly in section, illustrating various parts of the loadcenter seen in FIG. 1;

FIG. 7 is a rear elevational view of the support block and neutral assembly seen in FIG. 1;

FIG. 8 is an end view of a bus assembly illustrating another embodiment of the invention; and

FIG. 9 is a sectional view taken along the line 1XIX of FIG. 8.

Referring to the drawings, there is shown in FIG. 1 a loadcenter 3 comprising an enclosure 5. The enclosure 5 comprises a receptacle 7 and a cover 9. The receptacle 7 comprises a generally planar metallic base plate or base part 11 and sidewall means 13 comprising four generally planar side walls extending from the base part 11 normal to the base part 11 to an open front. The cover 9 is removably connected to the receptacle 7 by means of a screw 15.

An insulating block 19, comprising a one-piece rigid insulating member of molded insulating material, is supported on the base plate 11 by means of a rivet 21 (FIG. 2). The insulating block 19 is provided with cavity means therein comprising a first cavity part 23 (FIGS. 3 and 5) and a second cavity part 25. As can be seen in FIG. 5, the cavity parts 23, 25 are open at the bottom side of the insulatin block 19. Each of the cavity parts 23, 25 comprises a terminal-connector receiving cavity part 27 (FIGS. 5 and 6) and a stab-receiving cavity slot or part 29. As can be seen in FIG. 3, each of the cavity parts 27 is open at two opposite sides of the support block 19. A bus assembly 31 (FIG. 6) is supported in the cavity part 23 and a similar bus assembly 33 (FIGS. 5 and 6) is supported in the cavity part 25. Only the bus assembly 33 is shown in the associated cavity in FIG. 5 and the cavity 23 that would receive the bus assembly 31 is open for the purposes of description. It will be understood with reference to FIGS. 1-6 that both of the bus assemblies 31 and 33 are positioned in the cavity means of the insulating support block 19 and captured in place when the insulating support 19 is mounted on the base plate 11.

Each of the bus assemblies 31, 33 comprises a planar fiat stab part 37 that is bent-over at the lower end thereof to provide a planar flat terminal part 39 that is positioned along a plane that extends normal to the plane of the associated stab part 37. A separate screw-type solderless terminal connector 41 is connected to the part 39 of each of the bus assemblies 31 and 33. Each of the solderless terminal connectors 41 comprises an inverted generally U-shaped support part 43 having an opening 45 (FIG. 3) in each leg thereof. Each of the terminal parts 39 passes through the associated openings 45 in the legs of the associated part 43 to provide a terminal or base part for the associated screw-type solderless terminal 41. A separate screw 4-9 is threaded into a suitable tapped opening in the bight portion of each of the members 43.

During the assembly of the loadcenter 3, each of the screws 49 is screwed into position on the associated U-shaped support part 43, and each of the conductors 37, 39 is connected to the associated part 43 by moving the part 39 into the openings 45 (FIG. 3) in the legs of the associated part 43 to thereby provide the bus assemblies 31, 33 as seen in FIG. 6. Thereafter, each of the bus assemblies 31, 33 is moved up into the associated cavity part 23, 25 (FIG. 5) through the bottom opening of the insulating support block 19 with each stab 37 moving into the associated cavity slot 29 and with each solderless terminal connector 41 moving into the associated cavity part 27 to the position seen in FIGS. 1-4. Thereafter, a flat insulating plate 51 is placed on the base part 11 of the receptacle 7 and the insulating block 19, with the bus assemblies 31, 33, is placed down on the insulating plate 51. Thereafter, the rivet 21 is passed up through or down through suitable openings in the plate 11, insulating plate 51 and insulating support block 19, and riveted over to the position seen in FIG. 2 to thereby fixedly support the insulating support block 19 on the base 11 with the bus assemblies 31, 33 captured in place as seen in FIGS. 1-4. Two tangs 55 (FIGS. 1 and 2) are struck up from the base 11 to engage the insulating block 19 to prevent rotation of the insulating block 19 on the base plate 11. As can be seen in FIGS. 1 and 3, the insulating block 19 is molded with a pair of well openings 57 open at the front just above the cavity parts 27 to provide access for screwdrivers that can be moved into the wells 57 to work the screws 49. As can be seen in FIG. 1, the stab parts 37 protrude out through the side cavity slots 29 to be accessible to receive connection with clip plug-in or clip-on type. terminal structures of circuit breakers 59 that are mounted in the load-center and connected to the stabs 37. Each of the circuit breakers 59 may be of the type disclosed in the patent of L. W. Dyer, Patent No. 2,677,- 025, issued Apr. 27, 1954 and assigned to the assignee of the-instant case. A metallic support plate 63, having two ledge parts 65 thereon is fixedly connected to the base plate 11 by means of a rivet 67. Each of the circuit breakers 59 comprises an insulating housing having a slot therein at one lower end thereof and a plug-in or clip-n type connecting terminal structure at the opposite sides of the stab, at the other lower end thereof. Each of the circuit breakers 59 may be mounted in position by clipping a shoulder part at one end under the associated ledge part 65 and rotating the other end down into the connected position with the associated plug-in or clip-on terminal engaging the associated stab 37 at opposite sides of the stab to provide the connection in a well known manner.

As can be seen in FIG. 4, the insulating support block 19 is provided with a projection 67 molded integral therewith in each of the cavity slots 29. Each of the conductors 39, 37 is provided with a notch 69 therein at the associated stab part 37 which receives the associated projection 67 to limit movement of the conductors 37, 39 in the associated cavity part. As can be seen in FIG. 3, each of the parts 43 is provided with fiat bottom end surfaces of the legs thereof which flat bottom surface engage the flat insulating plate 51 at the open bottom of the associated cavity means to rest on the insulating plate 51 when the insulating block 19 is mounted in position. With the provision of the legs of each member 43 engaging the insulating plate 51 and with the provision of the slot 69 (FIG. 4) receiving the projection 67, along with the relatively close fit of the bus assembly in the cavity means, each of the bus assemblies 31, 33 is fixedly positioned to receive the forces thereon when a circuit breaker is plugged into position and when the associated screw 49 is rotated without substantial movement of the bus assembly in the cavity of the insulating support block 19.

A neutral assembly 71 (FIGS. 2 and 6), comprising a conducting plate 73 and four solderless terminal con.- nectors 75 connected on the conducting plate 73 in the same manner as the solderless terminals 41 are comnected on the associated parts 39, may be mounted on the insulating support block 19 and secured thereto by means of a rivet 75.

Whenthe insulating block 19 is in the mounted position seen in FIG. 1, a separate conductor 77 can be connected to each of the solderless or screw-type terminals 41 to electrically connect the circuit breakers 59 in circuit. Each of the conductors 77 comprises an uninsulated end part that is moved into the cavity part 27, which cavity part is open at the two opposite sides of the insulating block19, and movedinto position betweenthe legs of the associated member 43 under the associated adjusting screw 49 and over the associated terminal part 39 (FIG. 6) of the associated bus assembly; whereupon the associated screw 49 is screwed down into position to pressure connect the conductor :77 to the solderless terminal connector 41 to thereby electrically connect the circuit breaker, that'would be connected to the associated conducting stab 37, in circuit. 7

A modified form of the invention will be understood with reference to FIGS. 8 and 9 wherein a two-piece bus assembly 81 is disclosed. The two piece bus assembly 81 comprises a one-piece conductor 83 that is bent-over at one end thereof to provide a stab part- 85.;The conductor 83 is formed with loop part 87 at the other end which loop part 87 is provided with a tapped opening for receiving a screw 89. The end of the loop part '87 is forked to provide two-leg parts 91 that straddle part of the conductor 83 (FIG. 9). The lower ends of the legs 91 are bent over at 93 to provide support for the bus assembly. The stab part 85 is provided with a notch similar to the notch 69 '(FIG. 4) for receiving the projection 67 of the support block 19. The busassembly 81 is supported in the cavity 23 of the'insulating block 19 in the same manner as 'was described with reference to the bus assembly 31. A bus assembly similar to the bus assembly 81 may be supported in the .cavity 25 (FIG. 6) in the same manner as was described with reference to the bus assembly 33. 1

From the foregoing, it can be understood that there is provided by this invention an improved loadcenter comprising few parts that are relatively inexpensive to manu facture and assemble. The bus assemblies are moved into cavity means in an insulating block through a bottom opening of the insulating block and captured in place when the insulating block is secured to the base of a receptacle. The bus assemblies engage a fiat insulating plate that is positioned between the insulating blockand the base plate to limit downward movement of the bus assemblies, and the stab parts are provided with notch means that receive projecting parts of the insulating block to limit movement of the bus assemblies in the cavities whereby the bus assemblies are adequately supported in the cavities against the forces that may be applied thereto when circuit breakers are connected to the stabs or when the screws of the solderless terminals are worked to connect or disconnect conductors to the terminals.

While the invention has been. disclosed in accordance with the provisions of the patent statutes, it is to be understood that various changes in the structural details and arrangement of parts thereof may be made without departing from some of the essential features of the invention. It is desired, therefore, that the language of the appended claims be given as reasonably broad pretation as is permitted by the prior art.

I claim as my invention: w

1. A loadcenter comprising a base plate, an insulating support block having cavity meanstherein, a bus assembly in said cavity means, said bus assembly comprising a stab part and a screw-type terminal part, securing means securing said insulating support block tov said base plate to thereby capture said bus assembly in said cavity means.

2. A loadcenter according to claim 1, said cavity means being open at the bottom of saidsupport block, said bus assembly-being positioned in said cavity means through said openbottom of said support block, an insulating plate between said 'base plate and the bottom of said support 'block, and said securingmeans securing said support block on said base plate capturing said insulating plate between said support block and said base plate and capturing said bus assembly in said cavity means between said insulating plate and said support block.

3. A loadcenter according to claim 2, said screw-type terminal part comprising a screw member rotatable to pressure-connect a conducting line to said screw-type teran inter-f minal part, and said insulating support block having an opening at the front thereof above said screw member to receive a screwdriver that may be used to work said screw member to connect a conducting line to said screw-type part.

4. A loadcenter according to claim 1, said stab part comprising a flat planar stab part, said bus assembly comprising a flat planar connector part extending from said stab part along a plane normal to the plane of said stab part, said stab part and said connector part being a onepiece conductor, said screw-type terminal part comprising a generally U-shaped part having an opening in each of the legs thereof and a tapped opening in the bight portion thereof, a screw in said tapped opening, said connector part being positioned in said openings in the legs of said U-shaped part under said screw whereby said bus assembly is a three-piece assembly comprising said one-piece conductor, said U-shaped part and said screw.

5. A loadcenter according to claim 4, said cavity means being open at the bottom of said support block, said bus assembly being positioned in said cavity means through said open bottom of said support block, an insulating plate between said base plate and the bottom of said support block, said securing means securing said support block on said base plate capturing said insulating plate between said support block and said base plate and capturing said bus assembly in said cavity means between said insulating plate and said support block, and the free ends of said U-shaped part of said screw-type terminal part engaging said insulating plate at said open bottom of said support block to support said bus assembly on said insulating plate.

6. A loadcenter according to claim 5, said stab part having notch means therein, said insulating support block having a projection molded integral thereon, and said projection extending in said notch means to provide additional support of said bus assembly in the mounted position of said bus assembly.

7. A loadcenter according to claim 6, a pair of said bus assemblies, said insulating support block having a pair of said cavity means therein, each of said bus assemblies being positioned in one of said cavity means, and said securing means comprising a single securing member securing said support block on said base plate capturing said insulating plate between said support block and said base plate and capturing said pair of bus assemblies in said pair of cavity means between said insulating plate and said support block.

8. A loadcenter according to claim 1, said bus assembly comprising said stab part a connector part and said screwtype terminal part all of which parts are integral parts of one-piece conductor, said stab part comprising a flat planar stab part at one end of said one-piece conductor, said connector part extending from said stab part along a plane normal to the plane of said stab part, said screwtype terminal part comprising a loop formed at the other end of said one-piece conductor, said loop having a tapped opening therein, a screw in said tapped opening, said as sembly being a two-piece assembly comprising said onepiece conductor and said screw.

9. A loadcenter according to claim 8, saidcavity means being open at the bottom of said support block, said bus assembly being positioned in said cavity means through said open bottom of said support block, an insulating plate between said base plate and said support block, said securing means securing said support block on said base plate capturing said insulating plate between said support block and said base plate and capturing said bus assembly in said cavity means between said insulating plate and said support block, and said one-piece conductor at said other end thereof engaging said insulating plate at said open bottom of said support block to support said bus assembly on said insulating plate.

10. A loadcenter according to claim 9, said stab part having notch means therein, said support block having a projection molded integral therewith, and said projection extending into said notch means to provide additional support of said bus assembly in the mounted position of said bus assembly.

References Cited UNITED STATES PATENTS 3,141,997 7/1964 Jacobs 317-119 XR 3,146,379 8/1964 Giger 317 119 3,328,553 6/1967 Gryctko 317-119 XR ROBERT K. SCHAEFER, Primary Examiner J. R. SCOTT, Assistant Examiner US. Cl. X.R. 3l7-119 

